Reactive liquid polymers are generally well known in industry. Typically such polymers include a polymeric backbone comprising primarly carbon to carbon bond and one or more terminal groups that may provide chemically reactive functionality. In addition, pendant groups that may provide reactive functionality may be present along the backbone. HYCAR.RTM. reactive liquid polymers manufactured by The BFGoodrich Company of Akron, Ohio are typical of such reactive liquid polymers.
Typically such liquid polymers are in an actual liquid state at or below conventional room temperatures. Occasionally, these materials may be semi-solid at room temperature but in a liquid form at temperatures below 200.degree. C. Owing to a termination group that may provide reactive or functional capabilities, these reactive liquid polymers tend to provide a mechanism for introducing a rubbery characteristic into compounds not otherwise demonstrating elastomeric properties.
So, for example, amine terminated butadiene/acrylonitrile liquid polymer (HYCAR ATBN 1300.times.16) may be introduced into an epoxy system to provide flexibility. Formulations of ATBN polymer with thermoplastic urethanes, castable elastomers, EPDM, and blended polymers find utility in providing desirable low impact characteristics in paint and primers used at temperatures substantially below 0.degree. F. ATBN polymers introduced into phenolic paint resins can assist in providing enhanced elongation characteristics in a finished phenolic paint coating. Reactive liquid polymers can find utility in the formulation of sealants where curing is desirable at room temperatures. Typically such a room temperature cure employs a epoxy resin as a curing agent. Systems of epoxy cured amine terminated reactive liquid polymers have found acceptance in applications such as underwater curable coatings.
Reactive liquid polymers may terminate in other than an amine group. For example, reactive liquid polymers may include terminal carboxylate, hydroxyl or vinyl functional groups or functional precursers. As might be expected, the nature of the reactivity of the reactive liquid polymer is substantially dependent upon the nature of the terminal entity.
Phosphazene is a well known compound comprising phosphorus and nitrogen and generally regarded as being a ring or chain polymer typically having two substituents on each phosphorus atom. Most typically the phosphazene is characterized by cyclic trimer, cyclic tetramer and high polymeric structures. It has been suggested that phosphazene be employed for cross-linking hydroxyl terminated liquid polybutadiene compounds and that phosphazene may be employed to provide substitution products in reactions with amines, alcohols and phenols and to activate carboxylic acid.
Limitations in epoxy cured-carboxyl terminated reactive liquid polymer systems relating to ultimate elongation and use at low temperatures would likely make cured amine terminated reactive liquid polymer systems having superior elongation and low temperature characteristics desirable. Rubbery like substances suitable for imparting impact enhancing properties and flame retarding properties alone or in combination with other polymers could find substantial utility.